How to measure weight

4(f) describe how to measure mass and weight by using appropriate balances.

 As covered in the previous post, mass and weight are two different quantities. Therefore, we use different equipment for the measurement of mass and weight. To measure the mass of an object, we use a beam balance. The use of a beam balance is covered in the previous post.

To measure the weight of an object, we use a Spring Balance. The following is a picture of a spring balance.

The object to be weighed is attached to the hook at the bottom. The spring stretches due to the weight of the object, and lowers down in the spring balance. The extension of the spring is directly proportional to the weight of the object, so that a heavier object would cause more extension. The spring balance gives readings in N, Newtons.


As the spring balance relies on the weight of an object to give readings, the readings would be different in different gravitational fields. An object which gives a reading of 10N on Earth would give much lower reading on the moon, due to lower gravitational strength of the moon.